/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ /* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is Mozilla.org code. * * The Initial Developer of the Original Code is * Boris Zbarsky . * Portions created by the Initial Developer are Copyright (C) 2002 * the Initial Developer. All Rights Reserved. * * Contributor(s): * Boris Zbarsky (original author) * L. David Baron , Mozilla Corporation * Mats Palmgren * * Alternatively, the contents of this file may be used under the terms of * either of the GNU General Public License Version 2 or later (the "GPL"), * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ #ifndef nsLayoutUtils_h__ #define nsLayoutUtils_h__ class nsIFormControlFrame; class nsPresContext; class nsIContent; class nsIAtom; class nsIScrollableView; class nsIScrollableFrame; class nsIDOMEvent; class nsRegion; class nsDisplayListBuilder; class nsIFontMetrics; #include "prtypes.h" #include "nsStyleContext.h" #include "nsAutoPtr.h" #include "nsStyleSet.h" #include "nsIView.h" #include "nsIFrame.h" class nsBlockFrame; /** * nsLayoutUtils is a namespace class used for various helper * functions that are useful in multiple places in layout. The goal * is not to define multiple copies of the same static helper. */ class nsLayoutUtils { public: /** * GetBeforeFrame returns the :before frame of the given frame, if * one exists. This is typically O(1). The frame passed in must be * the first-in-flow. * * @param aFrame the frame whose :before is wanted * @return the :before frame or nsnull if there isn't one */ static nsIFrame* GetBeforeFrame(nsIFrame* aFrame); /** * GetAfterFrame returns the :after frame of the given frame, if one * exists. This will walk the in-flow chain to the last-in-flow if * needed. This function is typically O(N) in the number of child * frames, following in-flows, etc. * * @param aFrame the frame whose :after is wanted * @return the :after frame or nsnull if there isn't one */ static nsIFrame* GetAfterFrame(nsIFrame* aFrame); /** * Given a frame, search up the frame tree until we find an * ancestor that (or the frame itself) is of type aFrameType, if any. * * @param aFrame the frame to start at * @param aFrameType the frame type to look for * @return a frame of the given type or nsnull if no * such ancestor exists */ static nsIFrame* GetClosestFrameOfType(nsIFrame* aFrame, nsIAtom* aFrameType); /** * Given a frame, search up the frame tree until we find an * ancestor that (or the frame itself) is a "Page" frame, if any. * * @param aFrame the frame to start at * @return a frame of type nsGkAtoms::pageFrame or nsnull if no * such ancestor exists */ static nsIFrame* GetPageFrame(nsIFrame* aFrame) { return GetClosestFrameOfType(aFrame, nsGkAtoms::pageFrame); } /** * IsGeneratedContentFor returns PR_TRUE if aFrame is generated * content of type aPseudoElement for aContent * * @param aContent the content node we're looking at. If this is * null, then we just assume that aFrame has the right content * pointer. * @param aFrame the frame we're looking at * @param aPseudoElement the pseudo type we're interested in * @return whether aFrame is the generated aPseudoElement frame for aContent */ static PRBool IsGeneratedContentFor(nsIContent* aContent, nsIFrame* aFrame, nsIAtom* aPseudoElement); /** * CompareTreePosition determines whether aContent1 comes before or * after aContent2 in a preorder traversal of the content tree. * * @param aCommonAncestor either null, or a common ancestor of * aContent1 and aContent2. Actually this is * only a hint; if it's not an ancestor of * aContent1 or aContent2, this function will * still work, but it will be slower than * normal. * @return < 0 if aContent1 is before aContent2 * > 0 if aContent1 is after aContent2, * 0 otherwise (meaning they're the same, or they're in * different documents) */ static PRInt32 CompareTreePosition(nsIContent* aContent1, nsIContent* aContent2, nsIContent* aCommonAncestor = nsnull) { return DoCompareTreePosition(aContent1, aContent2, -1, 1, aCommonAncestor); } /* * More generic version of |CompareTreePosition|. |aIf1Ancestor| * gives the value to return when 1 is an ancestor of 2, and likewise * for |aIf2Ancestor|. Passing (-1, 1) gives preorder traversal * order, and (1, -1) gives postorder traversal order. */ static PRInt32 DoCompareTreePosition(nsIContent* aContent1, nsIContent* aContent2, PRInt32 aIf1Ancestor, PRInt32 aIf2Ancestor, nsIContent* aCommonAncestor = nsnull); /** * CompareTreePosition determines whether aFrame1 comes before or * after aFrame2 in a preorder traversal of the frame tree, where out * of flow frames are treated as children of their placeholders. This is * basically the same ordering as DoCompareTreePosition(nsIContent*) except * that it handles anonymous content properly and there are subtleties with * continuations. * * @param aCommonAncestor either null, or a common ancestor of * aContent1 and aContent2. Actually this is * only a hint; if it's not an ancestor of * aContent1 or aContent2, this function will * still work, but it will be slower than * normal. * @return < 0 if aContent1 is before aContent2 * > 0 if aContent1 is after aContent2, * 0 otherwise (meaning they're the same, or they're in * different frame trees) */ static PRInt32 CompareTreePosition(nsIFrame* aFrame1, nsIFrame* aFrame2, nsIFrame* aCommonAncestor = nsnull) { return DoCompareTreePosition(aFrame1, aFrame2, -1, 1, aCommonAncestor); } /* * More generic version of |CompareTreePosition|. |aIf1Ancestor| * gives the value to return when 1 is an ancestor of 2, and likewise * for |aIf2Ancestor|. Passing (-1, 1) gives preorder traversal * order, and (1, -1) gives postorder traversal order. */ static PRInt32 DoCompareTreePosition(nsIFrame* aFrame1, nsIFrame* aFrame2, PRInt32 aIf1Ancestor, PRInt32 aIf2Ancestor, nsIFrame* aCommonAncestor = nsnull); /** * GetLastSibling simply finds the last sibling of aFrame, or returns nsnull if * aFrame is null. */ static nsIFrame* GetLastSibling(nsIFrame* aFrame); /** * FindSiblingViewFor locates the child of aParentView that aFrame's * view should be inserted 'above' (i.e., before in sibling view * order). This is the first child view of aParentView whose * corresponding content is before aFrame's content (view siblings * are in reverse content order). */ static nsIView* FindSiblingViewFor(nsIView* aParentView, nsIFrame* aFrame); /** * Get the parent of aFrame. If aFrame is the root frame for a document, * and the document has a parent document in the same view hierarchy, then * we try to return the subdocumentframe in the parent document. */ static nsIFrame* GetCrossDocParentFrame(nsIFrame* aFrame); /** * IsProperAncestorFrame checks whether aAncestorFrame is an ancestor * of aFrame and not equal to aFrame. * @param aCommonAncestor nsnull, or a common ancestor of aFrame and * aAncestorFrame. If non-null, this can bound the search and speed up * the function */ static PRBool IsProperAncestorFrame(nsIFrame* aAncestorFrame, nsIFrame* aFrame, nsIFrame* aCommonAncestor = nsnull); /** * Like IsProperAncestorFrame, but looks across document boundaries. */ static PRBool IsProperAncestorFrameCrossDoc(nsIFrame* aAncestorFrame, nsIFrame* aFrame, nsIFrame* aCommonAncestor = nsnull); /** * GetFrameFor returns the root frame for a view * @param aView is the view to return the root frame for * @return the root frame for the view */ static nsIFrame* GetFrameFor(nsIView *aView) { return static_cast(aView->GetClientData()); } /** * GetScrollableFrameFor returns the scrollable frame for a scrollable view * @param aScrollableView is the scrollable view to return the * scrollable frame for. * @return the scrollable frame for the scrollable view */ static nsIScrollableFrame* GetScrollableFrameFor(nsIScrollableView *aScrollableView); /** * GetScrollableFrameFor returns the scrollable frame for a scrolled frame */ static nsIScrollableFrame* GetScrollableFrameFor(nsIFrame *aScrolledFrame); static nsPresContext::ScrollbarStyles ScrollbarStylesOfView(nsIScrollableView *aScrollableView); /** * GetNearestScrollingView locates the first ancestor of aView (or * aView itself) that is scrollable. It does *not* count an * 'overflow' style of 'hidden' as scrollable, even though a scrolling * view is present. Thus, the direction of the scroll is needed as * an argument. * * @param aView the view we're looking at * @param aDirection Whether it's for horizontal or vertical scrolling. * @return the nearest scrollable view or nsnull if not found */ enum Direction { eHorizontal, eVertical, eEither }; static nsIScrollableView* GetNearestScrollingView(nsIView* aView, Direction aDirection); /** * HasPseudoStyle returns PR_TRUE if aContent (whose primary style * context is aStyleContext) has the aPseudoElement pseudo-style * attached to it; returns PR_FALSE otherwise. * * @param aContent the content node we're looking at * @param aStyleContext aContent's style context * @param aPseudoElement the name of the pseudo style we care about * @param aPresContext the presentation context * @return whether aContent has aPseudoElement style attached to it */ static PRBool HasPseudoStyle(nsIContent* aContent, nsStyleContext* aStyleContext, nsIAtom* aPseudoElement, nsPresContext* aPresContext) { NS_PRECONDITION(aPresContext, "Must have a prescontext"); NS_PRECONDITION(aPseudoElement, "Must have a pseudo name"); nsRefPtr pseudoContext; if (aContent) { pseudoContext = aPresContext->StyleSet()-> ProbePseudoStyleFor(aContent, aPseudoElement, aStyleContext); } return pseudoContext != nsnull; } /** * If this frame is a placeholder for a float, then return the float, * otherwise return nsnull. */ static nsIFrame* GetFloatFromPlaceholder(nsIFrame* aPossiblePlaceholder); // Combine aNewBreakType with aOrigBreakType, but limit the break types // to NS_STYLE_CLEAR_LEFT, RIGHT, LEFT_AND_RIGHT. static PRUint8 CombineBreakType(PRUint8 aOrigBreakType, PRUint8 aNewBreakType); /** * @return PR_TRUE if aFrame is the CSS initial containing block for * its pres-shell */ static PRBool IsInitialContainingBlock(nsIFrame* aFrame); /** * Get the coordinates of a given DOM mouse event, relative to a given * frame. Works only for DOM events generated by nsGUIEvents. * @param aDOMEvent the event * @param aFrame the frame to make coordinates relative to * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if * for some reason the coordinates for the mouse are not known (e.g., * the event is not a GUI event). */ static nsPoint GetDOMEventCoordinatesRelativeTo(nsIDOMEvent* aDOMEvent, nsIFrame* aFrame); /** * Get the coordinates of a given native mouse event, relative to a given * frame. * @param aEvent the event * @param aFrame the frame to make coordinates relative to * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if * for some reason the coordinates for the mouse are not known (e.g., * the event is not a GUI event). */ static nsPoint GetEventCoordinatesRelativeTo(const nsEvent* aEvent, nsIFrame* aFrame); /** * Get the coordinates of a given native mouse event, relative to the nearest * view for a given frame. * The "nearest view" is the view returned by nsFrame::GetOffsetFromView. * XXX this is extremely BOGUS because "nearest view" is a mess; every * use of this method is really a bug! * @param aEvent the event * @param aFrame the frame to make coordinates relative to * @param aView view to which returned coordinates are relative * @return the point, or (NS_UNCONSTRAINEDSIZE, NS_UNCONSTRAINEDSIZE) if * for some reason the coordinates for the mouse are not known (e.g., * the event is not a GUI event). */ static nsPoint GetEventCoordinatesForNearestView(nsEvent* aEvent, nsIFrame* aFrame, nsIView** aView = nsnull); /** * Translate from widget coordinates to the view's coordinates * @param aPresContext the PresContext for the view * @param aWidget the widget * @param aPt the point relative to the widget * @param aView view to which returned coordinates are relative * @return the point in the view's coordinates */ static nsPoint TranslateWidgetToView(nsPresContext* aPresContext, nsIWidget* aWidget, nsIntPoint aPt, nsIView* aView); /** * Given aFrame, the root frame of a stacking context, find its descendant * frame under the point aPt that receives a mouse event at that location, * or nsnull if there is no such frame. * @param aPt the point, relative to the frame origin * @param aShouldIgnoreSuppression a boolean to control if the display * list builder should ignore paint suppression or not */ static nsIFrame* GetFrameForPoint(nsIFrame* aFrame, nsPoint aPt, PRBool aShouldIgnoreSuppression = PR_FALSE); /** * Given aFrame, the root frame of a stacking context, paint it and its * descendants to aRenderingContext. * @param aRenderingContext a rendering context translated so that (0,0) * is the origin of aFrame * @param aDirtyRegion the region that must be painted, in the coordinates * of aFrame * @param aBackground paint the dirty area with this color before drawing * the actual content; pass NS_RGBA(0,0,0,0) to draw no background */ static nsresult PaintFrame(nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, const nsRegion& aDirtyRegion, nscolor aBackground); /** * @param aRootFrame the root frame of the tree to be displayed * @param aMovingFrame a frame that has moved * @param aPt the amount by which aMovingFrame has moved and the rect will * be copied * @param aCopyRect a rectangle that will be copied, relative to aRootFrame * @param aRepaintRegion a subregion of aCopyRect+aDelta that must be repainted * after doing the bitblt * * Ideally this function would actually have the rect-to-copy as an output * rather than an input, but for now, scroll bitblitting is limited to * the whole of a single widget, so we cannot choose the rect. * * This function assumes that the caller will do a bitblt copy of aCopyRect * to aCopyRect+aPt. It computes a region that must be repainted in order * for the resulting rendering to be correct. * * The region consists of: * a) any visible background-attachment:fixed areas in the after-move display * list * b) any visible areas of the before-move display list corresponding to * frames that will not move (translated by aDelta) * c) any visible areas of the after-move display list corresponding to * frames that did not move * d) except that if the same display list element is visible in b) and c) * for a frame that did not move and paints a uniform color within its * bounds, then the intersection of its old and new bounds can be excluded * when it is processed by b) and c). * * We may return a larger region if computing the above region precisely is * too expensive. */ static nsresult ComputeRepaintRegionForCopy(nsIFrame* aRootFrame, nsIFrame* aMovingFrame, nsPoint aDelta, const nsRect& aCopyRect, nsRegion* aRepaintRegion); /** * Compute the used z-index of aFrame; returns zero for elements to which * z-index does not apply, and for z-index:auto */ static PRInt32 GetZIndex(nsIFrame* aFrame); /** * Uses a binary search for find where the cursor falls in the line of text * It also keeps track of the part of the string that has already been measured * so it doesn't have to keep measuring the same text over and over * * @param "aBaseWidth" contains the width in twips of the portion * of the text that has already been measured, and aBaseInx contains * the index of the text that has already been measured. * * @param aTextWidth returns the (in twips) the length of the text that falls * before the cursor aIndex contains the index of the text where the cursor falls */ static PRBool BinarySearchForPosition(nsIRenderingContext* acx, const PRUnichar* aText, PRInt32 aBaseWidth, PRInt32 aBaseInx, PRInt32 aStartInx, PRInt32 aEndInx, PRInt32 aCursorPos, PRInt32& aIndex, PRInt32& aTextWidth); /** * Get the union of all rects in aFrame and its continuations, relative * to aFrame's origin. Scrolling is taken into account, but this shouldn't * matter because it should be impossible to have some continuations scrolled * differently from others. */ static nsRect GetAllInFlowBoundingRect(nsIFrame* aFrame); /** * Get the font metrics corresponding to the frame's style data. * @param aFrame the frame * @param aFontMetrics the font metrics result * @return success or failure code */ static nsresult GetFontMetricsForFrame(nsIFrame* aFrame, nsIFontMetrics** aFontMetrics); /** * Get the font metrics corresponding to the given style data. * @param aStyleContext the style data * @param aFontMetrics the font metrics result * @return success or failure code */ static nsresult GetFontMetricsForStyleContext(nsStyleContext* aStyleContext, nsIFontMetrics** aFontMetrics); /** * Find the immediate child of aParent whose frame subtree contains * aDescendantFrame. Returns null if aDescendantFrame is not a descendant * of aParent. */ static nsIFrame* FindChildContainingDescendant(nsIFrame* aParent, nsIFrame* aDescendantFrame); /** * Find the nearest ancestor that's a block */ static nsBlockFrame* FindNearestBlockAncestor(nsIFrame* aFrame); /** * If aFrame is an out of flow frame, return its placeholder, otherwise * return its parent. */ static nsIFrame* GetParentOrPlaceholderFor(nsFrameManager* aFrameManager, nsIFrame* aFrame); /** * Find the closest common ancestor of aFrame1 and aFrame2, following * out of flow frames to their placeholders instead of their parents. Returns * nsnull if the frames are in different frame trees. * * @param aKnownCommonAncestorHint a frame that is believed to be on the * ancestor chain of both aFrame1 and aFrame2. If null, or a frame that is * not in fact on both ancestor chains, then this function will still return * the correct result, but it will be slower. */ static nsIFrame* GetClosestCommonAncestorViaPlaceholders(nsIFrame* aFrame1, nsIFrame* aFrame2, nsIFrame* aKnownCommonAncestorHint); /** * Get a frame's next-in-flow, or, if it doesn't have one, its special sibling. */ static nsIFrame* GetNextContinuationOrSpecialSibling(nsIFrame *aFrame); /** * Check whether aFrame is a part of the scrollbar or scrollcorner of * the root content. * @param aFrame the checking frame * @return if TRUE, the frame is a part of the scrollbar or scrollcorner of * the root content. */ static PRBool IsViewportScrollbarFrame(nsIFrame* aFrame); /** * Return the value of aStyle as an nscoord if it can be determined without * reference to ancestors or children (e.g. is not a percentage width) * @param aStyle the style coord * @param aRenderingContext the rendering context to use for font measurement * @param aFrame the frame whose style context should be used for font information * @param aResult the nscoord value of the style coord * @return TRUE if the unit is eStyleUnit_Coord or eStyleUnit_Chars */ static PRBool GetAbsoluteCoord(const nsStyleCoord& aStyle, nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, nscoord& aResult) { return GetAbsoluteCoord(aStyle, aRenderingContext, aFrame->GetStyleContext(), aResult); } /** * Same as above but doesn't need a frame */ static PRBool GetAbsoluteCoord(const nsStyleCoord& aStyle, nsIRenderingContext* aRenderingContext, nsStyleContext* aStyleContext, nscoord& aResult); /** * Get the contribution of aFrame to its containing block's intrinsic * width. This considers the child's intrinsic width, its 'width', * 'min-width', and 'max-width' properties, and its padding, border, * and margin. */ enum IntrinsicWidthType { MIN_WIDTH, PREF_WIDTH }; static nscoord IntrinsicForContainer(nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, IntrinsicWidthType aType); /* * Convert nsStyleCoord to nscoord when percentages depend on the * containing block width. */ static nscoord ComputeWidthDependentValue( nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, nscoord aContainingBlockWidth, const nsStyleCoord& aCoord); /* * Convert nsStyleCoord to nscoord when percentages depend on the * containing block width, and enumerated values are for width, * min-width, or max-width. Returns the content-box width value based * on aContentEdgeToBoxSizing and aBoxSizingToMarginEdge (which are * also used for the enumerated values for width. This function does * not handle 'auto'. It ensures that the result is nonnegative. * * @param aRenderingContext Rendering context for font measurement/metrics. * @param aFrame Frame whose (min-/max-/)width is being computed * @param aContainingBlockWidth Width of aFrame's containing block. * @param aContentEdgeToBoxSizing The sum of any left/right padding and * border that goes inside the rect chosen by -moz-box-sizing. * @param aBoxSizingToMarginEdge The sum of any left/right padding, border, * and margin that goes outside the rect chosen by -moz-box-sizing. * @param aCoord The width value to compute. */ static nscoord ComputeWidthValue( nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, nscoord aContainingBlockWidth, nscoord aContentEdgeToBoxSizing, nscoord aBoxSizingToMarginEdge, const nsStyleCoord& aCoord); /* * Convert nsStyleCoord to nscoord when percentages depend on the * containing block height. */ static nscoord ComputeHeightDependentValue( nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, nscoord aContainingBlockHeight, const nsStyleCoord& aCoord); /* * Calculate the used values for 'width' and 'height' for a replaced element. * * http://www.w3.org/TR/CSS21/visudet.html#min-max-widths */ static nsSize ComputeSizeWithIntrinsicDimensions( nsIRenderingContext* aRenderingContext, nsIFrame* aFrame, const nsIFrame::IntrinsicSize& aIntrinsicSize, nsSize aIntrinsicRatio, nsSize aCBSize, nsSize aMargin, nsSize aBorder, nsSize aPadding); // Implement nsIFrame::GetPrefWidth in terms of nsIFrame::AddInlinePrefWidth static nscoord PrefWidthFromInline(nsIFrame* aFrame, nsIRenderingContext* aRenderingContext); // Implement nsIFrame::GetMinWidth in terms of nsIFrame::AddInlineMinWidth static nscoord MinWidthFromInline(nsIFrame* aFrame, nsIRenderingContext* aRenderingContext); static void DrawString(const nsIFrame* aFrame, nsIRenderingContext* aContext, const PRUnichar* aString, PRInt32 aLength, nsPoint aPoint); static nscoord GetStringWidth(const nsIFrame* aFrame, nsIRenderingContext* aContext, const PRUnichar* aString, PRInt32 aLength); /** * Derive a baseline of |aFrame| (measured from its top border edge) * from its first in-flow line box (not descending into anything with * 'overflow' not 'visible', potentially including aFrame itself). * * Returns true if a baseline was found (and fills in aResult). * Otherwise returns false. */ static PRBool GetFirstLineBaseline(const nsIFrame* aFrame, nscoord* aResult); /** * Derive a baseline of |aFrame| (measured from its top border edge) * from its last in-flow line box (not descending into anything with * 'overflow' not 'visible', potentially including aFrame itself). * * Returns true if a baseline was found (and fills in aResult). * Otherwise returns false. */ static PRBool GetLastLineBaseline(const nsIFrame* aFrame, nscoord* aResult); /** * Gets the closest frame (the frame passed in or one of its parents) that * qualifies as a "layer"; used in DOM0 methods that depends upon that * definition. This is the nearest frame that is either positioned or scrolled * (the child of a scroll frame). In Gecko terms, it's approximately * equivalent to having a view, at least for simple HTML. However, views are * going away, so this is a cleaner definition. */ static nsIFrame* GetClosestLayer(nsIFrame* aFrame); /** * Draw a single image. * @param aRenderingContext Where to draw the image, set up with an * appropriate scale and transform for drawing in * app units (aDestRect). * @param aImage The image. * @param aDestRect Where to draw the image (app units). * @param aDirtyRect Draw only within this region (rounded to the * nearest pixel); the intersection of * invalidation and clipping. * @param aSourceRect If null, draw the entire image so it fits in * aDestRect. If non-null, the subregion of the * image that should be drawn (in app units, such * that converting it to CSS pixels yields image * pixels). */ static nsresult DrawImage(nsIRenderingContext* aRenderingContext, imgIContainer* aImage, const nsRect& aDestRect, const nsRect& aDirtyRect, const nsRect* aSourceRect = nsnull); /** * Set the font on aRC based on the style in aSC */ static void SetFontFromStyle(nsIRenderingContext* aRC, nsStyleContext* aSC); /** * Convert an eStyleUnit_Chars nsStyleCoord to an nscoord. * * @param aStyle the style coord * @param aRenderingContext the rendering context to use for font measurement * @param aStyleContext the style context to use for font infomation */ static nscoord CharsToCoord(const nsStyleCoord& aStyle, nsIRenderingContext* aRenderingContext, nsStyleContext* aStyleContext); /** * Determine if any style coordinate is nonzero * @param aCoord the style sides * @return PR_TRUE unless all the coordinates are 0%, 0 or null. */ static PRBool HasNonZeroSide(const nsStyleSides& aSides); /** * Determine if a widget is likely to require transparency or translucency. * @param aFrame the frame of a , or element. * @return a value suitable for passing to SetWindowTranslucency */ static PRBool FrameHasTransparency(nsIFrame* aFrame); /** * Get textrun construction flags determined by a given style; in particular * some combination of: * -- TEXT_DISABLE_OPTIONAL_LIGATURES if letter-spacing is in use * -- TEXT_OPTIMIZE_SPEED if the text-rendering CSS property and font size * and prefs indicate we should be optimizing for speed over quality */ static PRUint32 GetTextRunFlagsForStyle(nsStyleContext* aStyleContext, const nsStyleText* aStyleText, const nsStyleFont* aStyleFont); }; #endif // nsLayoutUtils_h__